1. Field of the Invention
The invention relates to a headband for diagnostic instruments comprising a light source and an accumulator module.
2. Description of the Background Art
For diagnostic instruments carried on the head use is made of batteries or accumulators, hereinafter also referred to as accumulator modules, which are placed directly on the headband. They serve as an energy source for operating a light source carried on the headband.
Such a head band is, for example, known from U.S. Pat. No. 4,593,683. The accumulators are mounted at the back part of the head band in order to contribute to a weight counterbalance with the diagnostic instrument mounted at the forehead side of the person wearing the head band. The head band has, at its back part, two ends overlapping each other which can be fixed with respect to each other for adaptation to the size of the head and in the adjusted position. For this, the ends of the head band, which are guided in an overlapping manner in a housing, are recessed in the longitudinal direction and provided with internal teeth which are engaged by a pinion placed on a shank which extends out of the housing and can be turned by means of a rotary knob.
On the internet at http:\\www.keeler.co.uk the company of Keeler Ltd., GB, presents a head band comprising an opthalmoscope which, at its back part, includes a housing substantially adapted to the form of the head, in which housing the longitudinal adjustment mechanism for the ends of the band and electrical components are arranged and which thus has a large width or thickness. A nose extending above the height of the housing protrudes outwardly from the center of the housing, through which nose the shank extends such that it can be turned, wherein the rotary knob for the head band adjustment is placed at the free end of the shank. The accumulator arrangement consists of two portions connected by an upper bar. The accumulator arrangement can be slipped onto the nose of the housing, wherein contact elements of the accumulator come into contact with contact elements of the housing, thereby providing electric current to be fed into a lamp of the opthalmoscope.
A similar head band is also disclosed in US 2005/0128735 A1. This head band has a battery base unit wherein ends of the head band pass through said battery base unit. An accumulator module can be fitted to said battery base unit wherein two inclined ramps engage in two inclined recesses and a clip locks in place.
U.S. Pat. No. 7,210,810 B1 describes a head band comprising a closed front support part for a diagnostic instrument having an LED and comprising an open back support part, wherein a mechanism for adjusting and fixing the head band length is assigned to the ends of said open back support part, the mechanism having clasps substantially adapted to the shape of the human head and a rotary knob. Said mechanism is provided with a receiving means in which a battery clip can be inserted.
The prior art accumulator systems are not optimized with regard to volume and weight. The special complex assembly means for the accumulator render the back part of the head band very heavy. Moreover, the shape of these assembly means is not adapted ideally to existing head band geometries.